1. Field of the Invention
The present invention relates to a liquid crystal display device.
2. Description of the Related Art
JP 2009-301912 A describes a liquid crystal display device including a backlight unit that allows light beams from a light emitting diode light source to enter through the side surface of a light guide plate and performs optical path conversion to emit planar illumination light to a liquid crystal display panel. JP 2009-301912 A illustrates the structure in which a reflection sheet is disposed over the rear surface of the light guide plate including the light emitting diode light source, and a rim sheet having functions of light shielding and reflection is provided just above the light emitting diode light source through the intermediation of an optical sheet such as a prism sheet (FIG. 3).
In the structure of the backlight unit described in JP 2009-301912 A, part of the light emitted from the light emitting diode light source propagates through the optical sheet rather than the light guide plate, and hence light beams leak out to cause brightness unevenness or lower light use efficiency. To address the problem, it is conceivable that a sheet having a reflection function is adhered directly onto the top surface of an end portion of the light guide plate without the intermediation of an optical sheet, so as to be positioned just above the light emitting diode light source.
However, simply adhering the sheet having the reflection function onto the top surface of the end portion of the light guide plate requires a large margin to adhere. Accordingly, the liquid crystal display device needs a thick frame on the side on which the light emitting diode light source is disposed.